On the 10th of January , I accompanied him to Pozzouli, and the late Mr. Laing Meason was of the party. Here we succeeded in getting Sir Walter placed upon a heap of ruins, where he might see the remains of the Thermae, commonly called the Temple of Serapis. His observation was, that we might tell him anything, and he would believe at all, for many of his friends, and particularly Mr. Morritt, had frequently tried to drive classical antiquities, as they were called, into his head, but they had always found his “skull too thick”.
From John Gibson Lockhart’s “Memoirs of the Life of Sir Walter Scott”, The Temple of Serapis mentioned above is the Macellum of Pozzuoli, in the province of Naples. It was excavated in the 18th century, and a statue of Serapis was found there, indicating the site was a Serapeum.